title: Usefulness of the chaotropic effect in sample preparation for chromatographic analysis of acidic xenobiotics in human plasma.
abstract: In this study a new RP-HPLC with photo-diode array detection method for the determination of ibuprofen ((RS)-2-(4-isobutylphenyl)propionic acid) in human plasma samples was developed. Samples were prepared by SPE and analyzed by an isocratic elution mode over a C18 column using 80% methanol. A novel sample pretreatment method, based on the addition of ionic liquids possessing chaotropic ions to small human plasma sample (100 μL), was elaborated. 1-Butyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM BF4 ) were tested from the point of view of extraction yield. Quantification was based on calibration curve applying diclofenac as the internal standard. Owing to dilution of plasma sample by 2 mM aqueous solution of BMIM BF4 before SPE, appropriate sample purification and extraction yields higher than 95% with precision lower than 2% can be achieved. Linear coefficients of correlation (r(2)) were >0.99 in the range of 0.3-5 μg/mL ibuprofen concentration in plasma. The limit of quantification was 65 ng/mL and the detection limit for ibuprofen was 19.5 ng/mL.
authors.affiliation: Department of Analytical Chemistry, Medical University of Lublin, Lublin, Poland.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Flieger
authors.forename: Anna
authors.initials: A
authors.lastname: Czajkowska-Żelazko
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007052:Ibuprofen / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry; D015394:Molecular Structure; D012016:Reference Values; D052616:Solid Phase Extraction; D015262:Xenobiotics / Q000008:administration & dosage / Q000097:blood* / Q000737:chemistry
chemical_list: D015262:Xenobiotics; D007052:Ibuprofen
keywords: Chaotropic effect; Human plasma; Ibuprofen; Ionic liquids